This invention relates to boring bar assemblies and more particularly to such assemblies utilized in the field to rebore large diameter bores in machinery particularly steam turbines.
Large diameter boring apparatus herebefore used in the field utilized worm gears to provide high torque at low speed. As diameters increased further speed reductions and increased torque were required to keep the cutting tool at the proper speed. Belt drives with various sized pulleys or sheaves were utilized along with motor controls and were not completely satisfactory as they resulted in overheated and overloaded worm gears. Larger diameter worm gears could only be used in select applications. Alignment of the various drive components in the field was excessive at times B 30% of the time spent on a bore was spent on aligning the drive mechanism.